Cockroaches live in a wide range of environments around the world. Pest species of cockroaches adapt readily to a variety of environments, but prefer warm conditions found within buildings. Many tropical species prefer even warmer environments and do not fare well in the average household.

Cockroaches as structural pest fall into two general categories. Occasional invaders and those that breed and live in your home. Of the occasional invaders the most common are known as Smoky Brown, Oriental, and American cockroaches. These generally breed outdoors in sewer and drainage systems, under homes, septic tanks, and almost anywhere else they can find food and shelter. The German Cockroach will take up residence in cabinets, door frames, and any crack or crevice where they can feel safe. Treatment for the occasional invaders versus German Cockroaches is very different and varies with the level of infestation, chemical sensitivity, and building type.

Cockroaches leave chemical trails in their feces as well as emitting airborne pheromones for swarming and mating. These chemical trails transmit bacteria on surfaces.[citation needed] Other cockroaches will follow these trails to discover sources of food and water, and also discover where other cockroaches are hiding. Thus, cockroaches can exhibit emergent behavior, in which group or swarm behavior emerges from a simple set of individual interactions.